New Keys To Keeping A Diverse Planet

Variation in plants and animals gives us a rich and robust assemblage
of foods, medicines, industrial materials and recreation activities.
But human activities are eliminating biological diversity at an
unprecedented rate.

A new UC Davis study offers clues to how these losses relate to one
another -- information that is essential as scientists and land
managers strive to protect the remaining natural variation.

Sharon Strauss, a professor of evolution and ecology, and former
doctoral student Richard Lankau (now a post-doctoral researcher at the
University of Missouri-St. Louis and the University of Illinois),
studied competition among genetically varied plants of one species
(black mustard, Brassica nigra), and among black mustard and plants of
other species.

"This is one of the first studies to show that genetic diversity and
species diversity depend on each other," Lankau said. "Diversity within
a species is necessary to maintain diversity among species, and at the
same time, diversity among species is necessary to maintain diversity
within a species.

"And if any one type is removed from the system, the cycle can break
down, and the community becomes dominated by a single species."

The research was funded by the National Science Foundation. The
paper, titled "Mutual feedbacks maintain both genetic and species
diversity in a plant community," was published in the Sept. 14 issue of
the journal Science.